My son did something similar from his 3rd birthday to 4th birthday, and it was horrible. He was totally sassy, defiant, contradictory, mouthy, argumentative, and so on:
Me: Put on your underwear
Me: 5 minutes until dinner (5 minutes later) Dinner!
Son: (Glares at me and walks away to his room)
Me: Be gentle with the pets.
Son: (Kicks at the cat)
And so on..
Life was miserable. Only my bellowing, gut-pushing, holler forced the issue; I yelled loudly enough to make the metal sink fixtures "ping" in resonance. Think of the "Jerry Springer" show. That was our home several times a day. All day. For a year. But Jerry Springer has weekends off.
Did I mention that I am normally a quiet, contemplative bookworm? I hated the yelling as much as everyone else.
If you are wondering: We offered him choices in the matters: Spiderman underwear or Buzz Lightyear underwear, but he argued; we provided 5 minute warnings for everything, but he ignored us; I always made a point to treat animals gently; he disobeyed.
I think this was his version of the terrible twos, but 1 year late. Other kids vary, I imagine. People may say he wanted to test his limits, find himself. Whatever. That's another conversation.
Then one day - shortly after his 4th birthday - I realized that I had not yelled at him in a week. Wait a second, what happened? He no longer picked fights, the 10 minutes-5minutes notices for dinner worked smoothly, and the cat started sleeping on his bed at night. I wondered if I got a new son. Jerry Springer was gone.
I heard that kids learn to understand reasonable conversations at this age, and we have a much happier home. This difficulty at least is done.