Indicative Verb Mood expresses and makes factual and authentic statements. For an example, ''A human is a mammal.'' It is true and a fact that a human is a mammal. Note that I leave no benefit of a doubt, but I state it matter of factly.
The Imperative Verb Mood expresses and makes a request and/or demand. Say for instance, ''Hand me that remote.'' Note that the speaker is telling you to do the action expressed, which was handing 'that' remote.
Subjunctive Verb Mood overall expresses doubts, suggestions, hypotheticals, and/or wishes. They normally use words like 'if'. For an example, ''If only I were that smart I'd enter and win that contest.'' Note that the speaker uses 'if'.
A1: Imperative because the person saying this sentence is telling us to look out the window and tell them what we see.
A2: Indicative because it's stating a fact.
A3: Subjunctive because it's making a wishful statement that proclaims *IF* they were us, they'd hike up Bridal Veil Falls.
A4: Again, subjunctive, because it's making a wishful statement. It outright says *if* as well as *wish*.
If your choices are the following:
A. Ivan Ilyich's has a dreaded fall that eventually leads to his illness.
B. Ivan Ilyich's colleagues react to finding out about his death and reminisce about his life.
C. Ivan Ilyich carries on a successful professional life and a deteriorating family life, when the onset of his illness occurs.
D. Ivan Ilyich lives out his full life story, from a young boy to a public prosecutor to a member of the Court of Justice.
Then the answer is c.