Sentence Correction (SC) | Re: The manager of the plastic fork factory tried to convince the unruly f

The managers convinced that ... is the correct form.

(A) they should join forces to optimize production on the belt rather than attempting to be contrary.--> Run on sentence.

(B) that they should join forces to optimize production on the belt rather than attempt to be contrary.

(C) about joining forces to optimize production on the belt instead of attempting to be contrary. -->Convinced about is incorrect. + Instead of and gerund is incorrect.

(D) for the joining of forces to optimize