Question

Fill in the blank with a relative pronoun:
A parallelogram ________ four sides are equal is called a rhombus.

• A. that
• B. whose
• C. whom
  
• D. which

Answer 1

Answer: (B)

whose

Since the sentence indicates possession or relation, that is sides possessed by the parallelogram, a possessive relative pronoun should be used, that is "whose". Hence, Option B is correct. The rest of the options do not adhere to this rule, hence incorrect.