1987 AJHSME Problem 4

Martians measure angles in clerts. There are 500 clerts in a full circle. How many clerts are there in a right angle?

\text{(A)}\ 90 \qquad \text{(B)}\ 100 \qquad \text{(C)}\ 125 \qquad \text{(D)}\ 180 \qquad \text{(E)}\ 250

Full credit goes to MAA for authoring these problems. These problems were taken on the AOPS website.