The question is based on a multiple-choice test scenario where a correct answer adds 4 points and an incorrect answer subtracts 1 point. The candidate in question scored 74 points.

Option 1 infers that the candidate left 4 questions unattempted. A net total of 74 points could be achieved by correctly answering 19 questions and incorrectly answering 2, which equals 76 marks (19*4) -2 (2*-1), which equates to 74 marks. Thus, 19 + 2 = 21 total attempts were made, meaning 4 were left unattempted (25 - 21 = 4).

Option 2 suggests that 3 questions were not answered, which doesn`t quite align with the scoring system.

Option 3 suggests 5 questions remained unattempted, which would not result in a score of 74.

Option 4 implies that 9 questions remained unmarked, which is not possible given the scoring system and total score achieved.

Therefore, the correct answer is Option 1- the candidate must have left 4 questions unattempted to get 74 marks.