A ring of mass m₁ and radius R is fixed in space at some location. An external agent brings a point mass m₂ from infinity to centre of the ring . Work done by the external agent will be

• A

  $-\frac{G{m}_1{m}_2}{R}$

• B

  $\frac{G{m}_1{m}_2}{R}$

• C

  $\frac{G\sqrt{m_1^2 + m_2^2}}{R}$

• D

  $\frac{G{m}_1{m}_2}{R(m_1^2 + m_2^2)}$