A particle is projected with an initial velocity at an angle of $45 ^ { \circ }$ to the horizontal. It reaches its maximum height at $\mathrm { t } = 2 \mathrm {~s}$ and passes the top of a building at $\mathrm { t } = 3 \mathrm {~s}$ after projection. Find the height of the building.\\
(A) 10 m\\
(B) 15 m\\
(C) 20 m\\
(D) 25 m