Which code segment could be used to properly implement a custom module called `temp_fahrenheit_rankine.py` to convert temperatures between Fahrenheit and Rankine scales?

A. In file `temp_fahrenheit_rankine.py` place

```python
"""Converts temperatures between Fahrenheit and Rankine"""

def to_rankine(fahrenheit):
"""Accepts degrees Fahrenheit
Returns degrees Rankine"""
rankine = fahrenheit + 459.67
return rankine

def to_fahrenheit(rankine):
"""Accepts degrees Rankine
Returns degrees Fahrenheit"""
fahrenheit = rankine - 459.67
return fahrenheit
```

B. In file `temperature.py` place

```python
"""Converts temperatures between Fahrenheit and Rankine"""

def to_rankine(fahrenheit):
"""Accepts degrees Fahrenheit
Returns degrees Rankine"""
rankine = fahrenheit + 459.67
return rankine

def to_fahrenheit(rankine):
"""Accepts degrees Rankine
Returns degrees Fahrenheit"""
fahrenheit = rankine - 459.67
return fahrenheit
```

C. In file `temperature.py` place

```python
""""Converts temperatures between Fahrenheit and Rankine""""

def to_rankine(fahrenheit):
rankine = fahrenheit + 459.67
return rankine

def to_fahrenheit(rankine):
fahrenheit = rankine - 459.67
return fahrenheit
```

D. In file `temp_fahrenheit_rankine.py` place

```python
"""Converts temperatures between Fahrenheit and Rankine"""

def to_rankine(fahrenheit):
"""Accepts degrees Fahrenheit
Returns degrees Rankine"""
rankine = fahrenheit + 459.67
return rankine

def to_fahrenheit(rankine):
"""Accepts degrees Rankine
Returns degrees Fahrenheit"""
fahrenheit = rankine - 459.67
return fahrenheit
```

The correct code segment for the custom module temp_fahrenheit_rankine.py to convert temperatures between Fahrenheit and Rankine scales is option D, which contains two functions with parameters for the respective conversions and a proper comment structure.

Explanation:

The proper implementation for a custom module called temp_fahrenheit_rankine.py that converts temperatures between Fahrenheit and Rankine scales is to define two functions within the module. One to convert Fahrenheit to Rankine and another to convert Rankine to Fahrenheit. In this scenario, the correct code segment is:

""" Converts temperatures between Fahrenheit and Rankine """

def to_rankine(fahrenheit):
""" Accepts degrees Fahrenheit
Returns degrees Rankine """
rankine = fahrenheit + 459.67
return rankine

def to_fahrenheit(rankine):
""" Accepts degrees Rankine
Returns degrees Fahrenheit """
fahrenheit = rankine - 459.67
return fahrenheit

This code segment takes a temperature in Fahrenheit, adds 459.67 to it to convert to Rankine, and does the reverse to convert from Rankine to Fahrenheit.