Teleconferencing is widely used nowadays to establish communication among those who are in the work from home modality; _____, this allows the participants to hear or see each other in a meeting.

A conjunctive adverb is a word that acts as a link between two independent clauses in a sentence. It can also come in between two main clauses, interrupting a single main clause. Examples of such conjunctive adverbs are although, therefore, then, moreover, although, etc.

In the given sentence, "teleconferencing" helped not only in establishing communication with the workers from their respective homes. It also "allows the participants to hear or see each other in a meeting". Thus, the best conjunctive adverb will be "moreover" as it adds to the already understandable sentence and links the two main clauses.

Thus, the correct answer is "moreover".