Answer :
Final answer:
The correct side ring that matches a rim base stamped with 'b7520 fl' according to the OSHA rim matching chart is 'c. 20 x 7.5 fl', as it has the required 'fl' designation for the flange.
Explanation:
According to the OSHA rim matching chart, a rim that is stamped with b7520 fl should match with a side ring that has a corresponding flange type. This means the matching side ring would need to have the same flange designation and rim size. Considering the options provided, the correct match would be c. 20 x 7.5 fl. The 'fl' in the side ring designation means it is a flanged ring, which matches the flange type on the base. Options 'a' and 'b' would not be correct as they have different designations ('la' and 'ms') that do not match the 'fl' flange type required for a proper and safe fit.