The correct answer is: (A) is correct, but (R) is incorrect.
Assertion (A) is correct because it is a common practice for firms to go to external sources for lower entry jobs. This is because these jobs often require less specialized skills and experience, which can be found in a wider pool of candidates from the external market.
Reason (R) is incorrect because it is not always the case that firms must go to external sources for positions where required qualifications or experiences are not met. In some cases, firms may be able to find qualified candidates from within their own organization. For example, they may be able to promote employees from lower-level positions or hire recent graduates who have the necessary skills and experience.
In conclusion, assertion (A) is correct because it is a common practice for firms to go to external sources for lower entry jobs. Reason (R) is incorrect because it is not always the case that firms must go to external sources for positions where required qualifications or experiences are not met.