MSRA-1201

A 25-year-old man visits his General Practitioner with a complaint of a sore throat that has been bothering him for the past three weeks. He reports feeling significantly fatigued, which is affecting his academic performance. On examination, he appears healthy and has tender cervical lymphadenopathy; his tonsils are enlarged but no exudate is present, and he has tender splenomegaly.
Which of the following investigation findings is most likely to be associated with this condition?
Select the SINGLE most appropriate result from the list below.