A krebs cycle intermediate, which act as raw material for chlorophyll production is synthesized after
A. Condensation
B. Substrate level phosphorylation
C. Hydration
D. Dehydrogenation

Hint:-The krebs cycle also known as citric acid or tricarboxylic acid cycle. Chlorophyll production is caused by the formation of a porphyrin ring from succinyl coenzyme A. Succinyl coenzyme A is used in heme manufacture and chlorophyll biosynthesis. Carbon dioxide and hydrogen are released during the process.

Complete step-by-step solution:-
The krebs cycle was first postulated by Hans Krebs in 1937. According to him it was an efficient pathway for the cells to produce energy during degradation of molecules. Carbon dioxide and hydrogen are broken down to acetyl coenzyme A before oxidation. Oxidative decarboxylation of succinyl CoA from alpha-ketoglutarate is catalysed by the enzyme alpha-ketoglutarate dehydrogenase. The reaction occur as a result of dehydrogenation and release carbon dioxide and hydrogen. Alpha-ketoglutarate contains five carbon molecules and succinyl coenzyme A contains 4 carbon molecules. One carbon molecules is released in the form of carbon dioxide. The final stages of the Krebs cycle include 4-carbon compounds. Krebs cycle is regulated by various enzymes. Krebs cycle intermediates such as succinate, alpha-ketoglutarate and oxaloacetate are removed and used as precursors of amino acid.
Condensation reaction is an additional reaction in which two molecules undergo condensation to form one molecule. Hydration reaction occurs in presence of water. Chlorophyll production in krebs cycle is synthesized after dehydrogenation. So the correct option is (D) dehydrogenation.

Note:-
 Krebs cycle is an integral part of adenosine triphosphate. This process takes place in mitochondria. It involves dehydration, hydration, decarboxylation and dehydrogenation reactions that produce adenosine triphosphate. The waste product removed in the form of carbon dioxide can be further used to regenerate the original reaction.