The correct answer is A) in the 'tripped' position. When the operating handle of a molded-case circuit breaker is in the mid-position, it indicates that the circuit breaker has been tripped, meaning the circuit has been interrupted and the breaker is in the open position. This is a safety feature that triggers the breaker to open the circuit when it detects an overcurrent or short circuit condition, preventing potential damage to the electrical system. The other options are incorrect because: B) 'closed' position means the breaker is allowing current to flow, C) 'opened' position means the breaker has been manually switched off, and D) 'reset' position is when the breaker has been re-engaged after being tripped.