Mitochondrial DNA Codes for About 13 Proteins (Depending on the Species

Mitochondrial DNA codes for about 13 proteins (depending on the species of organism) .These 13 proteins account for a small proportion of the proteins present in mitochondria.The remaining proteins are coded for by nuclear DNA.What is the most likely explanation for how these proteins find their way to the mitochondria?

A) signal sequences
B) random transport vesicles
C) attachment of ribosomes to outer mitochondrial pores and direct deposition into the inner mitochondrial compartment
D) mRNAs that are manufactured in the nucleus,but translated by mitochondrial ribosomes