What observation about light supported Einstein’s theory?

Explanation:

Do you mean the theory that space-time is defined by what's in it? And that mass warps space-time?

There are many instances where his observation turned out to be correct. The most popular one is the phenomena of gravitational lensing. We can see the light from stars that are actually behind the sun. The huge gravity of the sun bends space-time and this also bends light. We use gravitational lensing a the time when trying to see very distant stars or galaxies.

if a star is moving toward earth, its light waves appear to be squeezed together. hope it

if you already have the answer to (a), then just work out how many periods there are in 1 minute, and that's the answer to (c).