What should come in place of the question mark (?) in the given series?
620 621 624 629 636 ?
A643
B645
C646
D644
A643
B645
C646
D644
Related Questions:
In a certain code language, 'rivers trees grass' is coded as '22 44 66' and 'trees clouds birds' is coded as '44 99 88'. How is 'trees' coded in the given language?