'Get' is usually followed by participle form of verb to describe the intended result. Here the correct phrase is 'get resolved with this attitude'.
'That' is a singular determiner, and it cannot be used with plural noun 'attitudes'. Similarly, 'those' (plural determiner) cannot be used with 'attitude'(singular noun).
The use of 'gets' is incorrect as 'them' is plural pronoun so it should be followed by a plural verb.
The correct sentence is- 'You're so busy defending yourself that nothing gets resolved with this attitude.'
Hence, option (c) is correct.
NOTE/-
Participle: A word formed from a verb (e.g. going, gone, being, been) and used as an adjective (e.g. working woman, burnt toast) or a noun (e.g. good breeding). In English participles are also used to make compound verb forms (e.g. is going, has been). Consider the sentences given below:
Dancing at the party, the women fell on the ground.
Encouraged by her parents, Rita went on to pursue her passion.
The highlighted word in the first sentence is of the form Verb + ing and is used as a present participle. It is used to denote an action that is going on or incomplete or imperfect.
The highlighted word in the second sentence is of the form verb + ed. It is used as a past participle. It denotes completed action or state of the thing spoken of.
A past participle ends with the following: -ed, -d, -t, -en, or -n.