Choose the correct statements about the hydrides of group 15...

On moving down the group from $NtoBi$, the atomic size increases. Consequently, the electron density on the central atom decreases and the basic strength decreases.

With an increase in size, the $M - H$bond becomes weaker, hence, the thermal stability decreases down the group.

The highest bond length will have less bond energy, indicating that it is a strong reducing agent.

On moving down the group, bond strength of M–H bond decreases, which reduces the thermal stability but increases reducing nature of hydrides,

Hence $A$ and $B$ are correct statements.