Answer:
B. an amino terminal signal peptide
Explanation:
The reactions of the citric acid cycle occur in the matrix of mitochondria. Therefore, all the enzymes required for this pathway are present in the matrix of mitochondria. These enzymes are formed on the ribosomes present in the cytosol and are transported into the mitochondria with the help of cytosolic heat shock proteins. The newly formed mitochondrial proteins have signal sequences present at their N terminal. The proteins to be transported into the matrix have a single signal sequence that at N terminal which is removed by a protease once the enzyme enters into the matrix.