What is NOT TRUE about the wobble effect in the genetic code

What is NOT TRUE about the “wobble” effect in the genetic code?

A the third position in codon assignments is variable.

B because of the wobble effect certain amino acids have multiple codons assigned to them.

C the third position in codon assignments is always constant.

D the first and second position in a codon are always constant.

Solution

I think the option is D because the first and second position in a codon are not always constant when compared to remaining positions.So option D is correct.