PLEASE HELP

Need an equation in D1 to find the number immediately greater then number in
col C, then copy the number beside from col B to D.

For example:
for 500 in col C, immediate greater number in col A is 569.3 and the number
beside in col B is 79, then the equation in D1 should give 79. (Column B has
numbers that sometime increasing sometime decreasing)

A B C D
71.162 100 500
142.325 98 100
213.487 95 200
284.65 90 300
355.813 88 400
426.975 85 500
498.138 81 600
569.3 79 700
640.462 76 800