Answer:
D. Due to the availability of solar energy, Diatom mass peaks in July.
Step-by-step explanation:
Diatom are the photosynthetic algae which prepare food for themselves from the solar radiation just like plants. These diatoms produce more biomass or vegetation in the summer season mainly in July because availability of more sunlight in the Barents sea region while on the other hand, less biomass in the winter season due to low temperature and solar radiation which also effects the population of zooplankton organisms. So we can conclude that seasonal changes have a great impact on the organisms living around the Barents Sea.