Fast !

a new solar system with two planets of equal mass - planet x and planet y - is discovered. planet x is closest to the sun.

what is the sun's gravitational pull on planet y as compared with planet x?

a.
because planet y is farther from the sun, the sun's gravitational pull on planet y is less than the sun's gravitational pull on planet x.
b.
the sun's gravity repels planet y with more force than it repels planet x, which is why planet y is farther away.
c.
because planet y is farther from the sun, the sun's gravitational pull on planet y is more than the sun's gravitational pull on planet x.
d.
the sun's gravitational pull on planet y is equal to its gravitational pull on planet x because distance does not affect the sun's gravity.

We're told that the planets have EQUAL MASS.

If that's true, then the strength of the gravitational forces between
each planet and the star depends only on the distance between
them ... the farther a planet is from the star, the smaller the
gravitational forces are IF we're talking about planets with
equal masses.

Planet-X is closer to the star, and Planet-Y is farther from it. 
From this we know that the gravitational forces between the
star and Planet-X are greater, and the forces between the star
and Planet-Y are smaller.

'A' says this.

'B' is totally absurd, because it talks about gravity repelling things.

'C' says exactly the opposite for the two planets.

'D' says that distance doesn't matter.  We know this is absurd,
simply because we're never pulled toward Jupiter in our daily life.