Select the most appropriate synonym of the underlined word in the given sentence.
The environmental organisation issued a statement to condemn the deforestation happening in the protected area.

The correct answer is Censure.

Let's analyze the given sentence and the meaning of the underlined word:
"The environmental organisation issued a statement to condemn the deforestation happening in the protected area."

Here, the word condemn means to express complete disapproval of, or to criticize someone or something strongly, especially for moral reasons. In the context of deforestation in a protected area, the organisation is expressing strong disapproval or criticism of this action.

Now, let's look at the options provided:
1. Censure: This verb means to express severe disapproval of someone or something, especially in a formal statement. This is a direct synonym of "condemn".
2. Persuade: This means to convince someone to do or believe something through reasoning or argument. This is unrelated to criticizing.
3. Foster: This means to encourage or promote the development of something. This is opposite in sentiment to the organization's stance against deforestation.
4. Compel: This means to force or oblige someone to do something. This is not a synonym for criticizing or expressing disapproval.

Therefore, Censure is the most appropriate synonym for condemn in this sentence.