The correct option is B Mature eggs
Mature egg secretes a chemical known as fertilizin, which is composed of glycoprotein (monosaccahride and fatty acid substance). Sperm has on its surface a protein substance known as antifertilizin, which is composed of acidic amino acids. The fertilizin and antifertilizin interacts together and this interaction makes the sperms stick to the egg surface. Hence, option B is correct answer.