The earth is an approximate sphere. If the interior contained matter which is not of the same density everywhere, then on the surface of the earth, the acceleration due to gravity:
 

The following are the given statements:
 

Choose the correct alternatives:

1. (b, d)

2. (a, c)

3. (c, d)

4. (a, c, d)

If the mass of the sun were ten times smaller and gravitational constant G were ten times larger in magnitude. Then,
 

Choose the correct alternatives:
1. (a, b, c)

2. (a, d)

3. (b, c, d)

4. (a, c, d)