Richard isn't driving right now. Last year, Richard rode his bicycle to work every day, but he has been taking the bus since the accident.
Why? You're speaking about something that started in the past, so you can't use takes. He has taken the bus more than once, so you can't use took.
You could say he has taken the bus:
Last year, Richard rode his bicycle to work every day, but he has taken the bus since the accident.
However, the inclusion of the first sentence in your example means that the focus is on the continuous state of Richard's actions in the present.
This means that:
Richard isn't driving right now. Last year, Richard rode his bicycle to work every day, but he has been taking the bus since the accident.
sounds more natural.
However, this is pretty nuanced and I would mark neither 2 nor 4 as incorrect. I am surprised that these are offered as exclusive options in the question you gave. Are you sure you can't pick multiple options?