Answer
See answer below
Work Step by Step
if A is an $n × p$ matrix and $D = diag(d_1,d_2,...,d_n)$
then $(DA)_{ij}=\sum \limits_{k=1}d_i \delta _{ik} a_{kj}=d_i\delta_{ii}a_{ij}=d_ia_{ij}$
Therefore, DA is the matrix obtained by multiplying the i-th row vector of $A$ by $d_i$, where $1\leq i \leq n$.
