The number of correct statements from the following is ___________.

A. For $1 \mathrm{s}$ orbital, the probability density is maximum at the nucleus

B. For $2 \mathrm{s}$ orbital, the probability density first increases to maximum and then decreases sharply to zero.

C. Boundary surface diagrams of the orbitals encloses a region of $100 \%$ probability of finding the electron.

D. p and d-orbitals have 1 and 2 angular nodes respectively.

E. probability density of p-orbital is zero at the nucleus