Need your help

It seems like you're asking to point out where in the passage(s) answer choice (A) is supported. If that is not your question, please clarify and we will make sure to answer. The following sentences all support answer choice (A): "Clay is an important constituent of many, if not all, drilling muds." Passage A "Drilling muds are made of bentonite and other clays and polymers," (lines 12-13). So we know drilling muds are made of bentonite and other clays. The author of Passage A using the adjective "other" for clay means that bentonite is also a clay. The author is saying that drilling muds are made of bentonite (a type of clay) and other clays. Passage B "One type of mud - water-based mud (WBM) - is a mixture of water, bentonite clay and chemical additives," (lines 38-40). Here the author of passage B is telling us that WBM is made up of three main ingredients, one of which is clay. So, as you can see, both passage A and B support answer choice (A), whereas there is never any mention of drilling mud being continuously discharged into the sea during the drilling of an oil well. That is why answer choice (E) is the correct answer and answer choice (A) is not. Hope that helped! Let us know if you need any clarifications.

How can we tell that clay is an important ingredient? The passage never explicitly mentioned that clay is an important ingredient, just that it is an ingredient.

Hi @Andrew, Happy to help! We learn from Passage B that bentonite is a type of clay (see line 39). Passage A tells us that "drilling muds are made of bentonite and other clays and polymers" (lines 12-14). The muds contain both bentonite clay and other clays which are then mixed with fluid. Therefore, we can conclude that clay must be an important constituent of drilling muds because they are a required component of the base that is then mixed with fluid to create the mud. Hope this helps! Please let us know if you have any further questions.