Final answer:
Lymphogranuloma (B) is not primarily a sexually transmitted infection. Genital herpes, Chlamydia, and Gonorrhea are all STIs caused by specific pathogens and can lead to severe complications if untreated.
Step-by-step explanation:
The answer to the question, "Which one of the following is not primarily a sexually transmitted infection (STI)?" is Lymphogranuloma (B). The rest of the options - Genital herpes (A), Chlamydia (C), and Gonorrhea (D) - are well-known sexually transmitted infections. Genital herpes is usually caused by the herpes simplex virus and can present as cold sores or genital lesions. Chlamydia is a common STI caused by the bacterium Chlamydia trachomatis, and gonorrhea is caused by Neisseria gonorrhoeae. Both can lead to severe complications if left untreated. Non-sexually transmitted diseases like lymphogranuloma are often confused with STIs because they can cause similar symptoms, such as swollen lymph nodes in the genital area.