The following experiment was performed to test the effect of auxin on the plant growth . Five plant seedlings ( all growing actively ) were prepared as below , they were unilaterally illuminated ,and growth was measured after 10 days.
Treatments :
Plant A : Tip not removed , nothing applied
Plant B : Tip removed , nothing applied
Plant C : Tip removed , gelation block with cytokinin was placed on the cut edge
Plant D : Tip removed gelation block with auixn placed on the cut edge.

Options

A. A and B
B. A and D
C. B and C
D. A, B, C and D

Answer

B