The correct option is A as though
In the given sentence, the subordinate clause "her life depends on it" depends on the main clause "She works" for its full meaning. The sentence speaks about the manner in which she is working is such that her life seems to depend on it. The given options are compound conjunctions, or phrases that perform the role of a conjunction, they link together clauses/sentences. 'As though' expresses the manner or behaviour of someone, and the subordinate clause is an assumption made, an imaginary situation that may or may not be true. It is relevant to the given statement, because here too, the person (she) works in a manner that would make someone believe that her life depends on it. Hence option A is correct. 'On condition that' expresses a conditional statement, where the subordinate clause is a condition on the basis of which the action in the main clause takes place. This isn't the situation here, she does not work on the condition that her life depends on it. Hence option B is incorrect. 'In order that' is used in purpose-related sentences, where the subordinate clause is the purpose or reason behind the action in the main clause, and the sentence here does not imply a purpose. 'As well as' is used to merely add a clause to another and not modify it in terms of meaning. It does not apply here, as the subordinate clause is an imaginary situation that requires a conjunction that expresses the manner in which she works. Hence option D is incorrect.