Let A = {1, 2, 3,.......,10} and
\(\mathrm{B}=\left\{\frac{\mathrm{m}}{\mathrm{n}}: \mathrm{m}, \mathrm{n} \in \mathrm{~A}, \mathrm{~m}<\mathrm{n} \text { and } \operatorname{gcd}(\mathrm{m}, \mathrm{n})=1\right\}\).
Then n(B) is equal to :
1
31
2
36
3
37
4
29