NEET 2005 Physics question

Imagine a new planet having the same density as that of earth but it is 3 times bigger than the earth in size. If the acceleration due to gravity on the surface of earth is g and that on the surface of the new planet is g', then :

• (A)g' = 3gCorrect
• (B)g' = g/9
• (C)g' = 9g
• (D)g' = g/3