Answer: C) Helioseismology Explanation: Helioseismology is the study of the solar interior using observations of waves on the Sun's surface. It has done much to improve our understanding of the interior of the Sun, testing the physical inputs used to model stellar interiors and providing a detailed map of the Sun's structure and internal rotation.

3 (5 M+5 W)=600
          5( 10 M+ 20 W)=3500

Solving we can get:

M=18

W=26

So we can find

Days =1060/6M+4W=5 days