Final answer:
The word that best completes the sequence is ‘mild’.
Step-by-step explanation:
In the given sequence, each word starts with the same letter as the previous word and contains four letters. The first word ‘high’ starts with ‘h’. The next word should also start with ‘h’ and contain four letters. The word that best completes the sequence is ‘mild’.
Out of the given options, the word ‘mild’ fits the criteria and completes the sequence: high -> absurd -> delight -> start -> mild.