Step 1: Understanding the Concept: While most sexually transmitted infections (STIs) can be completely cured if detected early and treated with antibiotics, some viral infections remain lifelong.
Step 2: Key Formula or Approach: Identify the STIs from the given options that are caused by specific viruses known to integrate into the host system and evade complete eradication.
Step 3: Detailed Explanation: According to standard medical knowledge and NCERT textbooks, diseases such as syphilis, gonorrhoea, chlamydiasis, and trichomoniasis are completely curable with proper medical treatment.
However, specific viral infections like Hepatitis-B, Genital herpes, and HIV infection (which causes AIDS) are currently considered not completely curable.
Option (4) lists both AIDS and Genital herpes, making it the only pair where both diseases are strictly non-curable.
While genital warts (caused by HPV) can be persistent, they are treatable and often clear up, whereas HIV, Herpes, and Hep-B are strictly categorized together as non-curable STIs in textbooks.
Step 4: Final Answer: The correct option is (4).