Explanation:

Determiners are words that are used before nouns to provide more information about the noun. In this case, the determiner is used to specify the quantity or amount of Maths that one must learn every day to improve.

The most appropriate determiner to fill in the blank in this sentence is "a little". Here's why:

1. The context:
The sentence is suggesting that in order to improve in Maths, one must dedicate a certain amount of time or effort to studying it every day. Therefore, the determiner should indicate a small or moderate amount of Maths that needs to be learned each day.

2. The options:
a) "a few" suggests a small number of items or people. However, Maths is not countable in the same way as tangible objects, so this option is not suitable.
b) "a little" suggests a small or moderate amount of something. This fits the context of the sentence, as it implies that one should dedicate some time to learning Maths every day.
c) "a lot of" suggests a large quantity or a significant amount. While it is important to put effort into learning Maths, the sentence does not indicate that one needs to spend a large amount of time every day.
d) "none of these" is not the correct option, as "a little" is the most appropriate determiner in this case.

3. The meaning:
Using "a little" implies that dedicating a small amount of time or effort to learning Maths each day will help improve one's skills over time. It suggests consistency rather than overwhelming oneself with excessive amounts of study material.

Therefore, the most appropriate determiner to fill in the blank in this sentence is "a little".

To choose the most appropriate determiner to fill in the blank, let's analyze the options:
- a few: This determiner is used when referring to a small number of things or a small amount of something. However, in this context, it doesn't fit well because we are talking about learning Maths every day, which implies a consistent and regular practice.
- a little: This determiner is used when referring to a small amount of something non-countable. In this case, it is the most appropriate option because we are talking about improving in Maths, which is a subject that cannot be counted in terms of individual units.
- a lot of: This determiner is used when referring to a large quantity or number of something. However, it doesn't fit well in this context because it implies a significant amount of time or effort, which might not be feasible for everyone.
- none of these: This option is not the correct answer as we have already determined that "a little" is the most appropriate determiner.
In conclusion, the most appropriate determiner to fill in the blank is "a little." Learning a little Maths every day will help improve one's skills gradually over time.