Question

Obdiplostemonous condition is that in which the stamens are in two whorls and
A. Outer whorl is fused to inner whorl
B. Outer whorl is opposite to petals
C. Inner whorl is opposite to petals
D. Both, inner as well as outer whorls are opposite to petals.

Answer 1

A whorl or verticil is an assembly of leaves, sepals, petals, stamens, or carpels that surround or wrap around the stem or stalk and radiate from a single point. At least three elements consist of a leaf whorl; a pair of opposite leaves is not called a whorl. It is fairly rare for leaves to develop in whorls, except in plant species with very short internodes.

Complete answer:
The word down into its component parts, they add up to exactly what it describes; it is formed from opposite, plus diplo- (Greek diploos, doubled or doubled), plus stemon, the Greek word for a thread (our stamen is the Latin equivalent), plus the adjective ending-ous. It also relates to two sets of stamens that are located opposite. In botany, it is one of a large number of descriptive terms that appear in formal family, genus or species descriptions.
The obdiplostemonous state of stamens occurs when the stamens of the outer whorl alternate with the representatives of the first whorl opposite the petals and those of the second whorl. There are twice as many stamens as petals in the flowers, which are opposite the petals in the outer set.

Hence, the correct answer is option (B).

Note: Obdiplostemonous has long been a controversial condition as it differs from diplostemony found by the alternisepal stamens' more external insertion. Obdiplostemonous is an amalgamation of at least five distinct pathways of floral production. Both of them contribute to the external placement in a two-whorled androecium of the alternisepalous stamen whorl.