La persona con quien fui a la fiesta era mi padre

Question

Greetings everyoneI would like to ask why the correct answer is the option:La persona con quien fui a la fiesta era mi padrewhile the answerLa persona con la que fui a la fiesta era mi padreis marked as nearly correct when both options are acceptable, according to the lesson above.

Accepted Answer

Hola Stavroula
Both answers are set as correct in the system:
con la que / con quien 
This is a multiple answer type question where, as it says when you are presented with this question "[one, some or all may be correct]" - The system gives you a "nearly correct" message because you are missing some other options there that are correct. It's not that your specific answer is nearly correct. 
I hope this clarifies it.
Saludos cordiales
Inma

Answer

The system marks you as nearly correct when you get one answer out of two correct answers. So it’s not the answer with “con la que” that is marked as nearly correct, it’s that you checked one correct answer when the system wanted you to check both correct answers.