Among the options provided, sexually transmitted infections (STIs) caused by bacteria are typically curable with antibiotics, while those caused by viruses are not curable but can be managed.

Option A : HIV infection and Trichomoniasis - HIV is a viral infection and currently has no cure, but it can be managed with antiretroviral therapy. Trichomoniasis is a parasitic infection and is curable with antibiotics.

Option B : Syphilis and Trichomoniasis - Both syphilis and trichomoniasis are curable. Syphilis is a bacterial infection and can be cured with antibiotics, typically penicillin. Trichomoniasis, as mentioned above, is a parasitic infection that can also be cured with antibiotics.

Option C : Hepatitis – B and Genital herpes - Both are viral infections and, while their symptoms can be managed, they are not curable.

Option D : Genital herpes and Genital warts - Both are caused by viruses (Herpes simplex and Human papillomavirus respectively) and, while their symptoms can be managed, they are not curable.

So, the correct answer is :

Option B : Syphilis and trichomoniasis.