Explanation:
The element that has the noble gas configuration plus 14 f-electrons plus 10 d-electrons in its core is thallium (Tl).

Here is the detailed explanation:

1. Noble Gas Configuration:
The noble gas configuration refers to the electron configuration of a noble gas, which is a group of elements with a stable electron configuration. Noble gases have a completely filled outermost electron shell, making them chemically stable. The noble gas that comes before thallium in the periodic table is xenon (Xe). The electron configuration of xenon is [Kr] 5s2 4d10 5p6.

2. F-electrons:
The f-electrons refer to the electrons in the f sublevel of the atom. The f sublevel can hold a maximum of 14 electrons. In the case of thallium, it has 14 f-electrons in addition to the noble gas configuration.

3. D-electrons:
The d-electrons refer to the electrons in the d sublevel of the atom. The d sublevel can hold a maximum of 10 electrons. In the case of thallium, it has 10 d-electrons in addition to the noble gas configuration and the f-electrons.

4. Electron Configuration of Thallium:
To determine the electron configuration of thallium, we start with the noble gas configuration of xenon and add the additional f-electrons and d-electrons.

The electron configuration of thallium is:

[Xe] 6s2 4f14 5d10

This configuration represents the noble gas xenon, followed by 6s2, which accounts for the two electrons in the 6s sublevel, 4f14, which accounts for the 14 f-electrons, and 5d10, which accounts for the 10 d-electrons.

Therefore, the correct answer is option 'C' - Thallium (Tl).

Thallium