You Had a Cold Last Month and You Caught Another

Multiple Choice

You had a cold last month and you caught another one this month from your brother. What is the most likely reason for this happening?

A) Memory cells were not formed as a response to the first cold.
B) The antibodies formed as a response to the first cold were degraded.
C) The two cold viruses are different.
D) Your macrophages are unable to perform phagocytosis.
E) Your antigen-presenting cells do not recognize the second cold virus.