After reading the sentence it is evident that meetings of boarder with her boy friend were unwanted, therefore matron put an end to these. So, we shall first find a word, which can easily fit into the second blank. ‘Stoic’ means humble, as meetings can’t be humble, therefore option (1) is ruled out. ‘Comatose’ means lethargic as if in coma, as we cannot relate this word to the meeting, therefore, option (2) is ruled out. ‘Baleful’ means destructive, ominous, deadly or harmful', now though meetings are described as undesirable but they cannot be termed as deadly meetings, hence option (3) is ruled out. As meetings can’t be overt (open, not hidden), therefore option (5) is also ruled out. ‘Clandestine’ meaning secret, private fits our prediction for the second blank. Moreover, ‘lynx–eyed’ means having very keen sight also makes a perfect match-describing characteristic of matron. Hence, (4) is the answer.