Major source of NADPH for fatty acid synthesis is:

Reductases in fatty acid synthesis require NADPH as reducing power. Out of all the options, NADPH is produced by HMP shunt only. Insulin is lipogenic. It increases the production of enzymes of HMP shunt. Other minor pathways producing NADPH are:- Malic enzyme (NADP Malate Dehydrogenase) Cytoplasmic Isocitrate dehydrogenase Glutamate dehydrogenase