Which part of speech is the underlined word in the following sentence? Yet, we are all making a whole range of decisions.

The word 'Yet' at the beginning of a sentence linking it to the previous idea (creating contrast) functions as a conjunction (specifically, a coordinating/conjunctive adverb used as a conjunction). It connects ideas, showing contrast — similar to 'but' or 'however'. In this contextual use, it serves a conjunctive function. Hence option (2), Conjunction, is correct.