The correct option is
B less
The correct answer is Option B.
In the given sentence there is comparison being made between 'her' and 'her father'- the use of the word 'than' implies this.
Therefore, there can be two options- the girl is either 'less artistic' or 'more artistic' than her father.
Option B -'LESS' is therefore the correct option.
The other options are incorrect and not suitable because-
Option A- 'AS' is used when equality is implied. Thus it would be the correct answer if the girl and her father were equally artistic.
Option C- 'MUCH' is used for comparison only in questions and negative clauses. The given sentence is an affirmative sentence. Hence, though used for comparison, it is not the suitable answer.
Option D- 'LEAST- is the superlative degree and used to express the highest degree of a quality and is used when we talk about three or more things. Here we are only talking about two people. Hence Option D is not the correct option.
Hence Option B is the correct option.