The correct option is C QRPS
Since the first part of the sentence ends with a subordinating conjunction "that", it should end with a subordinating clause(Q). Since the subordinating clause initiates a condition, the condition should be completed in the next part(R)followed by an alternative(P) flanked by the final alternative(6).Hence, option C, that is, "St. Francis taught that if men would be happy they must be good and that it was easier to be good and happy if one were poor and did not trouble oneself with money." is correct. The rest of the options do not adhere to this logical sequence, hence incorrect.