Final answer:
DNA is the material contained in chromosomes within the cell nucleus that directs the cell's functions. It codes for proteins, which are synthesized at ribosomes in the cytoplasm, following the transcription and translation of genetic information. Option c is correct.
Step-by-step explanation:
The thin strands that contain genetic material for directing the cell's functions are DNA (deoxyribonucleic acid). DNA is a nucleic acid found within the nucleus of eukaryotic cells, tightly packed into structures called chromosomes. Each chromosome is a long, coiled molecule of DNA wrapped around proteins, containing genes that hold the code necessary for the synthesis of proteins.
In the process known as transcription, the information coded in DNA is used to create messenger RNA (mRNA), which exits the nucleus and travels to ribosomes in the cytoplasm. Ribosomes are the sites of protein synthesis, where the instructions carried by mRNA are translated into amino acid sequences, ultimately forming proteins. Although mitochondria also contain their own DNA, this DNA is specifically related to the organelle's functions and replication, and is distinct from the cell's chromosomal DNA that directs its general functions.