rely/trust and invasion/intrusion

Interpreting the feelings of other people is not always easy, as we all know, and we (61) ………….. as much on what they seem to be telling us, as on the actual words they say. Facial (62) …………… and tone of voice are obvious ways of showing our (63) .................. to something, and it may well be that we unconsciously express views that we are trying to hide. The art of being (64) ……… lies in picking up these signals, realizing what the other person is trying to say, and acting so that they are not embarrassed in any way. For example, we may understand that they are in fact (65) …………… to answer our question, and so we stop pressing them. Body movements in general may also indicate feelings, and interviewers often pay particular attention to the way a candidate for a job walks into the room and sits down. However it is not difficult to present the right kind of appearance, while what many employers want to know relates to the candidate’s character traits, and (66) ………….. stability. This raises the awkward question of whether job candidates should be asked to complete psychological tests, and the further problem of whether such tests actually produce (67) …………….. results. For many people, being asked to take part in such a test would be an objectionable (68) ……………….. into their private lives. After all, a prospective employer would hardly ask a candidate to run a hundred meters, or expect his or her family doctor to provide (69) …………… medical information. Quite apart from this problem, can such tests predict whether a person is likely to be a (70) ……………… employee or a values colleague?
Question 61: A. reckon B. rely C. trust D. estimate
Question68: A. invasion B. infringement C. intrusion
Please tell me why the key says not C but B for q61, not A but C for q68. And please help me understand the first sentence: we rely as much on what they seem to be telling us, as on the actual words they say.