Panjim's prepaid expense account consists only of garage rental prepayments. Its 2015 beginning and ending balance were the same. Which one of the following statements must be true?

• Panjim had no garage rental expenses during 2015
• Panjim's prepaid expense account balance never varied during 2015
• Panjim's prepaid expense account balance varied during 2015
• None of the above statements is true