Buehler Company on June 15^th sells merchandise on account to Chaz Co. for $1,000, terms 2/10, n/30. On June 20^th, Chaz Co. returns merchandise worth $300 to Buehler Company. On June 24^th, payment is received from Chaz Co. for the balance due. What is the amount of cash received?

A : $780

B : $686

C : $680

D : $700