Directions: In the sentence below, identify the part containing a grammatical or idiomatic error, if any. Ignore punctuation errors.

Building a supportive workplace is (A) / a continuing process that (B) / demand patience and flexibility (C) / from every manager (D) / No error (E)

The correct option is C.

Explanation:
To find the grammatical error, let us analyze the sentence step-by-step:

1. Subject-Verb Agreement in Relative Clauses:
In the clause "that demand patience and flexibility", the relative pronoun "that" refers back to the singular noun phrase antecedent "a continuing process".

2. Identifying the Error:
A relative pronoun takes a singular verb if its antecedent is singular. Because "process" is singular, the verb following "that" must also be singular. The base verb "demand" is plural, which creates a subject-verb agreement error. It should be replaced with the singular form "demands".

3. Corrected Sentence:
"Building a supportive workplace is (A) / a continuing process that (B) / demands patience and flexibility (C) / from every manager (D)"

Therefore, the part containing the error is C.