Concept:
Sports Psychology is a branch of psychology that studies human behaviour in sports and exercise settings. It applies psychological principles and techniques to improve athletic performance, motivation, concentration, confidence, and mental well-being.
It combines scientific study with practical application in sports environments.
Step 1: Examine Assertion (A).
The assertion states that psychological principles are applied in sports settings to enhance performance.
This statement is correct because Sports Psychology focuses on improving athletic performance using psychological methods.
Step 2: Examine Reason (R).
The reason explains that Sports Psychology scientifically studies people and their behaviour in sports contexts and applies this knowledge to improve performance.
This statement is also correct.
Step 3: Check whether the reason explains the assertion.
The reason clearly explains why Sports Psychology applies psychological principles in sports settings.
Hence:
\[
\boxed{\text{Both (A) and (R) are correct and (R) is the correct explanation of (A)}}
\]
Therefore, the correct answer is:
\[
\boxed{(A)}
\]