Olaf is an HR learning and development member planning a new training program for his company's software engineers. In a project status meeting, his manager suggests that Olaf may want to consider external training vendors because: Group of answer choices . using externally-developed materials ensures high quality external providers better understand adult learning theory external providers can always deliver training more cost effectively building a team of internal instructors may not be cost effective, depending on the range of topics and numbers of courses to be delivered