2020 Cayley Problem 11

The sum of the first 9 positive integers is 45; in other words,

1+2+3+4+5+6+7+8+9=45

What is the sum of the first 9 positive multiples of 5? In other words, what is the value of 5+10+15+\cdots+40+45?

\textbf{(A)}\ 225\quad \textbf{(B)}\ 250\quad \textbf{(C)}\ 180\quad \textbf{(D)}\ 150\quad \textbf{(E)}\ 450

If there are no answer choices shown, enter a numerical answer.

Full credit to this problem is given to the CEMC, you may view all Cayley contests here.