Writing Sample Question about Assumptions

MaeHeTadaHitazuraMaeHe

I am very new to practicing for the writing sample, so I have some questions that might seem like common sense to other people. I'm sorry.

I notice sometimes that when I'm arguing for a particular choice I catch myself wanting to fill in gaps with stated assumptions that are necessary for my point to logically follow. However, sometimes these include outside information or things that are not stated in the prompt. For example, one of the writing sample prompts from an older prep test stated two options for filling in the gaps in a shop owner's inventory: either adding a line of metalwork items from a regional artists consortium, or becoming the sole representative for the artwork in the estate of a deceased painter. This painter lived most of his life in the area but the majority of his works were painted elsewhere. One of the criteria is that the shop owner wants to specialize in locally produced artwork. I was wondering as I wrote if the line of metalwork from the regional artists consortium meant artwork made by regional artists producing in the region. In other words, as I was writing, I was assuming that the line of metalwork was made locally. In these occasions, even if I do not know for sure, should I clarify that that they were made locally?

Another question that I have is about including not just the facts in the prompt, but also considerations to support my arguments. Of course, I know I have to use the facts, but in addition to the facts, can I also write about considerations? For example, in the same practice essay I was writing about how the choice of adding the line of metalwork would help the shop owner fulfill her goal of attracting new customers, since sustainable art is in trend among environmentally conscious art collectors, but such a consideration is not a fact. I am assuming the truth that materials such as metal are more ecologically friendly compared to oil and paper, for example. But, then again, I am making the assumption that the paintings were not watercolors... Then I caught myself thinking that I'm also making the assumption here that the scraps of metal were responsibly disposed of and no mercury or other toxic metals were used. My common sense says most probably not or the artists would also be dead, but anyway, these thoughts still intrude as I write. I need some guidance, or maybe someone to smack me over the head.