Which sentence has correct punctuation? OA.
In physics class, Paolo is studying the strength-to weight ratio of building materials.
In biology class, Tyra is working with an expensive-phase-contrast microscope.
OB.
OC. In business class, Rita is learning to develop cost-effective marketing programs.
OD. In shop class, James is making a dining room table out of coarse grained wood.

Option C: In business class, Rita is learning to develop cost-effective marketing programs.

Explanation:

-Option A is lacking one en dash. The correct usage would be: In physics class, Paolo is studying the strength-to-weigth ratio of building materials.

-Option B has one too many en dashes. The usage would be: In biology class, Tyra is working with an expensive-phase contrast microscope.

-Option C is lacking an en dash. The correct usage would be: In shop class, James is making a dining room table out of course-grained wood.

1# the answer is c

2#the answer is a