Correct Answer: vain

Solution : The correct choice is the fourth option.

Explanation: Vain means having an excessively high opinion of oneself, especially regarding one's appearance.

In the context of the sentence, the actress is described as someone who takes pride in her appearance all the time, indicating excessive concern about how she looks.

The meanings of the other options are as follows:

• Vein : A tube that carries blood in the body; not suitable in the context of describing someone's attitude towards appearance.
• Wane : To decrease gradually; unrelated to describing someone's attitude towards appearance.
• Vane : A device that measures the direction of the wind; not suitable in the context of the sentence.

So, the correct sentence would be: "The actress is very vain and takes pride in her appearance all the time."