Explanation:
The correct answer is option 'D': such / that.

Reasoning:
In the given sentence, the phrase "he has difficulty finding shoes to fit him" indicates that the person mentioned in the sentence has a problem finding shoes that are suitable for his feet. This indicates a cause and effect relationship, where the size of his feet is the cause and the difficulty finding shoes is the effect.

To express this cause and effect relationship, the correct construction to use is "such...that." This construction is used to show that the extent or degree of one thing leads to a specific consequence or result.

Construction:
The construction "such...that" is used to connect two clauses in a cause and effect relationship. The word "such" is followed by an adjective or a noun phrase, and "that" is followed by a clause that expresses the consequence or result of the first part.

Example:
- The cat was so hungry that it ate all the food. (The extreme hunger of the cat led to it eating all the food.)

In the given sentence, the correct construction is:
- He has got such big feet that he has difficulty finding shoes to fit him.

Analysis of options:
a) as / as - This construction is used for making comparisons, but it does not convey the cause and effect relationship present in the sentence.

b) such / as - This construction is used for making comparisons, but it does not convey the cause and effect relationship present in the sentence.

c) so / that - This construction is similar to "such...that," but it is used to express a result or consequence without indicating the cause. It does not convey the cause and effect relationship present in the sentence.

d) such / that - This is the correct construction to express the cause and effect relationship between the size of the person's feet and the difficulty finding shoes.

e) more / than - This construction is used for making comparisons, but it does not convey the cause and effect relationship present in the sentence.

Therefore, the correct answer is option 'D': such / that.