To determine the correct answer, let's analyze the sentence and compare the degree of seriousness of the engine fault in the current situation with the last time.
The sentence structure suggests that the engine fault is more serious this time than it was the last time.
Now let's evaluate the options:
Option A:
much more serious
- This option correctly reflects the comparison of the degree of seriousness between the current situation and the last time. It implies that the engine fault is significantly more serious this time.
Option B:
as serious as
- This option suggests that the degree of seriousness is the same as the last time. However, the sentence indicates that the fault is more serious this time, making this option incorrect.
Option C:
so serious that
- This option implies that the seriousness of the engine fault is at a level that it causes a specific consequence. It doesn't convey the comparison between the current situation and the last time, so it is not the correct answer.
Option D:
a lot serious
- This option is grammatically incorrect. It should be "a lot more serious" to convey the comparison. Therefore, it is not the correct answer.
Option E:
far more seriously than
- This option is incorrect because it changes the adverb "serious" to an adverbial phrase "seriously," which alters the meaning of the sentence.
Therefore, the correct answer is option A:
much more serious
, as it accurately reflects the comparison of the degree of seriousness between the engine fault in the current situation and the last time.