His sudden outburst in the office was surprising because he’s never seemed  to lose control.

A  That he’s never seemed to lose control led to his sudden outburst in the office.

B He’s always seemed very self- controlled, so I was amazed by his sudden outburst in the office.

C His sudden outburst in the office showed that he’s never seemed to lose control.

D I was so amazed by his sudden outburst in the office that I seemed to lose control.