Choose the exact meaning of the underlined phrase.
Believe me, I am all at sea.

the environment in which the given expression is used through a judgment . 
For illustration, I worked hard to understand gospel but it turns out that indeed moment I'm all at ocean. 
Let us now dissect the given options to find the correct meaning of the expression. 
a) Out of reach means to be beyond one’s reach. 
For illustration, Her phone is out of reach. 
We observe that it isn't analogous to the contextual meaning of the expression. Hence, we can say that option ‘ a ’ isn't the correct answer. 
b) veritably happy means to be exhilarated or extremely joyous. 
For illustration, She must be veritably happy moment because she has won an award. 
We observe that it isn't analogous to the contextual meaning of the expression. Hence, we can say that option ‘ b ’ isn't the correct answer. 
c) Puzzled means confused or nonplussed . 
For illustration, She was puzzled by his tricky answers to her simple questions. 
We observe that it's analogous to the contextual meaning of the expression. Hence, we can say that option ‘ c ’ is the correct answer. 
d) Drowning means getting submerged in water. 
For illustration, The passerby saw the sprat drowning and rushed to their deliverance. 
We observe that it isn't analogous to the contextual meaning of the expression. Hence, we can say that option ‘ d’ isn't the correct answer. 
therefore, the correct answer is option ‘ c ’- “ puzzled ”.