Owen has an investment portfolio. You notice that $80\%$ of his portfolio is invested in a single stock. When you ask Owen about it$,$ he notes that he works in the same industry and knows a lot about it$,$ so he is sure that the stock will increase in price significantly. Which of the following biases may Owen be exhibiting?

a$.$

Illusion of control

b$.$

Conservatism

c$.$

Status$-$quo

d$.$

Cognitive dissonance