It’s definitely C. GoodLuck :)
Each tissue is an organized assembly of cells held together by cell-cell (more...) In epithelial tissue, by contrast, cells are tightly bound together into sheets called epithelia. The extracellular matrix is scanty, consisting mainly of a thin mat called the basal lamina, which underlies the epithelium.
What causes hemolytic disease of the newborn (HDN)? HDN most frequently occurs when an Rh negative mother has a baby with an Rh positive father. When the baby's Rh factor is positive, like the father's, problems can develop if the baby's red blood cells cross to the Rh negative mother.
You stroke the ball and roll down throat
Let a be Q, all which is homozygous recessive = Q∧2
A = p, AA which is homozygous recessive = Q∧2
2pq = heterozygous
It is derived from p+ q = 1
All those in a population which is Q = 20%
All A in the population (p) = 80%
Now that the disease is homozygous recessive therefore,
aa = qq or q × q = 0.20 × 2 = 4%
Then the answer is 4%.