Answer:
A. If neither parent expresses the trait, but the offspring does, both parents must be heterozygous for the trait.
Explanation:
If neither parents express the trait is because they are heterozygous and the dominant allele is being expressed over the recessive trait. When parents cross they have 25% of having an offspring that expresses the recessive trait, this means the offspring is a recessive homozygous. In the attached example 25% or 1/4 will have a short stem.
It survives by under water volcanoes like the marianas trench. :)
The defining characteristic of the intertidal zone is that it is submerged with water during high tide and exposed to the air during low tide. The zone can take many forms, from sandy beaches to rocky cliffs. It is common for the intertidal zone to change frequently, since it is constantly battered by crashing waves.
Hope this helped.