Which among the following is the major lipid found only in mitochondrial membrane?

Phosphatidic acid is a precursor of phosphatidylglycerol, which in turn gives rise to cardiolipin. This phospholipid is found only in mitochondria and is essential for the mitochondrial function. Decreased cardiolipin levels or alterations in its structure or metabolism cause mitochondrial dysfunction in aging and in pathological conditions including hea failure, hypothyroidism, and Bah syndrome (cardioskeletal myopathy). Ref: Botham K.M., Mayes P.A. (2011). Chapter 15. Lipids of Physiologic Significance. In D.A. Bender, K.M. Botham, P.A. Weil, P.J. Kennelly, R.K. Murray, V.W. Rodwell (Eds), Harper's Illustrated Biochemistry, 29e.