If $\alpha, \beta$ and $\gamma$ are the angles made by a vector with $\mathrm{x}, \mathrm{y}$ and z axes respectively, then $\sin ^2 \alpha+\sin ^2 \beta=$

• A

  $\sin ^2 \gamma$
• B

  $\cos ^2 \gamma$
• Correct answer
  C

  $1+\cos ^2 \gamma$
• D

  $1+\sin ^2 \gamma$

Hence, the correct answer is option: 'C'.