It can be inferred from the passage that the purpose of Colonno's experiments was to determine whether A. chimpanzees and humans can both be infected by rhinoviruses B. chimpanzees can produce antibodies to human cell-surface receptors C. a rhinovirus' nucleic acid might be locked in its protein coat D. binding antibodies to common receptors could produce a possible defense against rhinoviruses E. rhinoviruses are vulnerable to human anti-bodies