When mendel crossed true-breeding pea plants that have inflated pods (pp) with those that have constricted pods (pp), it was observed that f1 offspring had a genotype of pp. what would their phenotype be?

So the question is all about breeding two inflated pods. So the best answer would be this one: 
F1 has Pp genotype. It is heterozygous. If you have a dominant allele, you will get the 'dominant' phenotype no matter what you have on the other allele. Usually people use upper case letter as dominant allele and lower case letter as recessive allele. So, in this case P is inflated and p is constricted. The F1 phenotype is inflated pods.
I hope you are satisfied with my answer