Genetic cross question

The crossing of pure line (inbred strain) individuals whose phenotype are opposite for the genetic trait “V” will give a progeny composed of:

A) 50% of V and 50% of v
B) 100% v
C) 75% of V and 25% of v
D) 100% of V

Hi everyone, the answer is D).
I understand that the parents must be VV x vv to give offspring Vv so 100% have the allele V.
But how can we conclude tha the parents must be VV and vv from the fact that they are pure line individuals?
Thank you for your help!

Yes exactly, because it says pure line which mean they are true breeding

But then why they are not VV x VV?

@AriHoresh How would we conclude they will be 100% V ? and is true breeding the same as pure line, in-bread strain, Ive seen some inconclusive definitions