Question

Fill in the blank with the most appropriate option.
There are several kinds of mushrooms in Turkey ________ poisonous.

• A. they are
• B. that are
• C. which they are
• D. being

Answer 1

The correct option is B that are

Here, 'that are' is correct because that is used for referring to something that has already been mentioned or is already known about. Here, it is a known fact that several kinds of mushrooms in Turkey are poisonous.
'They' is used instead of he or she to refer to a person whose sex is not mentioned or not known. Example: They will be back by tomorrow! Moreover, 'they are' does not fit in the sentence.
'Being', as an uncountable noun, refers to your mind and all of your feelings. Example: She hated him with all her whole being.
'Which they are' does not fits in the sentence.