AHSME 1952 Problem 38

The area of a trapezoidal field is $1400$ square yards. Its altitude is $50$ yards. Find the two bases, if the number of yards in each base is an integer divisible by $8$. The number of solutions to this problem is: $\textbf{(A)}\ \text{none} \textbf{(B)}\ \text{one} \textbf{(C)}\ \text{two} \textbf{(D)}\ \text{three} \textbf{(E)}\ \text{more than three}$