All objects are in motion relative to the sun.
a. true
b. false

That depends on what "objects" refer to.
If "objects" refer to the ones on Earth, then it is TRUE. These objects are in motion relative to the sun same as with Earth itself.

If "objects" refer to the ones outside earth, then it may be a TRUE or FALSE depending on how far or near they are from the sun.

It should be d if not then c