Correct Answer  Option 2 : 6.67 × 10
11 Nm
2 Kg
2
CONCEPT:

Gravitational Force: between two masses m1 and m2 at the distance of R is given by:
\(F=G\frac{m_1m_2}{R^2} \)
where F is the gravitational force, m1 and m2 are the masses, and G is the gravitational constant.
EXPLANATION:
 The universal gravitational constant G is the universal constant.
 Its value does not change with place or time.
 The value of G is 6.67 × 1011 Nm2Kg2.
 Unit of G:
\(F=G\frac{m_1m_2}{R^2} \)
\(G=\frac{FR^2}{m_1m_2} \)
unit of G = unit of \(\frac{FR^2}{m_1m_2} \)
unit of G = \(\frac{N\times m^2}{Kg\times Kg} \)
 The unit of G is N m2 Kg2.
 So the correct answer is option 2.