"Fats and fixed oils are greasy (or) waxy (substance) that in (their) pure state are (normally) tasteles, colorless, and odorless. "

Is 'substance' a countable noun?

Or it can be uncountable or countable, based on the different meaning of it???

And, can we replace or by and , and why?

:-s Thank you!!
'Substance' is countable when it means a type of material, and uncountable when it means property or nature.

No, I would not replace 'or' with 'and'-- greasiness and waxiness are two different qualities. From the context, I would think that some fats are greasy and others are waxy; on the other hand, the author may be unsure whether the reader would consider all fats & fixed oils greasy or waxy, and is offering the two adjectives as alternatives.
Thank you so much, Mr. Micawber. Now I got it. The answer should be B). Emotion: smile