Step 1: The key descriptor is a creamy, curd like white patch on the tongue. This look is classic for oral thrush.
Step 2: Oral thrush is caused by Candida albicans. The white patches are soft, can be scraped off, and may leave a red raw base underneath. So option A is correct.
Step 3: Why the others are wrong. Histoplasmosis can cause oral ulcers, not a wipeable creamy patch, and is usually seen in immunocompromised or endemic disease. Lichen planus gives white lacy striae that cannot be scraped off, not curd like patches. Aspergillosis mainly affects lungs and sinuses, not the tongue surface as a curd patch.
Step 4: A creamy curd patch that scrapes off equals candidiasis.
Answer: Candidiasis.