Answer:
Option D, A subject is observed both before and after two exposures to the treatment.
Explanation:
In A-B-A-B design the alphabets have following meaning
a) First A – It is the baseline value or the value measured before treatment
b) First B – It is the treatment measurement
c) Second A - It is the withdrawal of treatment
d) Second B – It is the reintroduction of treatment
The second A is known as the reversal phase in which the intervention is withdrawn to see if the target behavior returns to the baseline behaviour
Thus , there are two measurements involved one before the intervention and second after the intervention
Option D is correct
In DNA, the nucleotides of one strand join to bases on the complementary strand by weak hydrogen bonds.
Egg cells are produced in the almond shaped organs. This is called the Female Reproduction System. Hope this helps. Got any questions? Just comment down below if you're unsure about my answer!
