54. The extraordinary dairy of William Lyon Mackenzie King, prime minister of Canada for over twenty years, revealed that this most bland and circumspect of men was a mystic guided in both public and private life by omens, messages received at seances, and signs from heaven.

a) same
b) that this most bland and circumspect of men was a mystic and also guided both in public as well as
c) this most bland..
d) this most bland..
e) this most bland..

Ans) A is correct choice.

My question.
I was able to elimate c, d, and e (needed the sentence to start with a 'that'). down to choice A and B, i had to pick B because in choice A, i thought "a comma" was missing after the word mystic? Shouldnt there be a comma or ; after the word mystic?

There doesn't need to be a comma, and, in fact, there shouldn't be one. Here we have the distinction between nonessential and essential modifiers:
ESSENTIAL modifiers, which DON'T have commas, narrow down the options for whatever you're describing. For instance:
(1) (correct) This painting shows soldiers digging trenches.
(2) (incorrect) This painting shows soldiers, digging trenches.
This needs to be the first one, because it creates increased specificity: not all workers dig trenches, so you're narrowing things down. Therefore, the modifier is ESSENTIAL (i.e., you'd lose meaning without it), and doesn't take a comma.

(3) (incorrect) Winters in New England with lots of snow can be brutal.
(4) (correct) Winters in New England, with lots of snow, can be brutal.
In this case you want #4, because ALL New England winters feature lots of snow. Therefore, the modifier doesn't narrow anything down - it merely clarifies things that are already implied by New England winters - and so it's NONESSENTIAL, requiring a comma.

In any case, this sentence would be grammatically OK with or without the comma (just as all 4 of the above examples are grammatically OK, even though two of them don't make sense semantically). Since there's no comma, we can infer that not all mystics fit the given description - but that's fine.

Choice B has a couple of problems:
* 'And also' implies that being a mystic has little or nothing to do with being guided in public and private life by all that stuff - clearly not the intended meaning.
* You can't use 'both' in the same construction as 'as well as'; to do so is both incorrect and redundant.