Aformal tone is most appropriate to use in ?
e-mails
essays
conversations
friendly letters

Essays

Essays tend to be written in a formal tone for various reasons. These essays are intended to mimic those that professional researchers write as part of their job. These are usually read by researchers all over the world, and therefore, a formal tone is necessary when you do not know your target audience. Moreover, using a formal tone makes it easier for others to understand what you are saying, as the English is standardized.

most likely the answer would be a.) cupidity

definitions:

cupidity - greed for money or possessions

hydrophobia - extreme or irrational fear of water, especially as a symptom of rabies in humans

pathology - the science of the causes and effects of diseases, especially the branch of medicine that deals with the laboratory examination of samples of body tissue for diagnostic or forensic

patho -   relating to disease

is this multiple choice?