For the above transitions in a `H-`like species, select the correct relation(s) :
A. `barv_(3)=barv_(1) + barv_(2)`
B. `v_(3)=(v_(1)v_(2))/(v_(1) + v_(2))`
C. `lambda_(3) = lambda_(1) + lambda_(2)`
D. `lambda_(3) = (lambda_(1)lambda_(2))/(lambda_(1)+lambda_(2)`