If \( \Large n \left(A\right)=6, n \left(B\right)=5, n \left(A\cap B\right)=3 \) then find \( \Large n \left(A\cup B\right) \)

A) 11

B) 9

C) 8

D) None of these

Correct answer:
C) 8

Description for Correct answer:
\( \Large n \left(A\cup B\right) = n \left(A\right)+n \left(B\right)-n \left(A\cap B\right) \)

= 6+5-3 = 8


Please provide the error details in above question