Which is NOT a sound argument?
a. Sabrina wanted to be a better figure skater, so she took extra lessons and practiced every day. Her skating improved so much that she entered a competition.
b. Yesterday, a black cat ran in front of me, and later, I lost my wallet. If I don't see that black cat today, I won't have any bad luck.
c. We had a storm last night with hurricane-strength winds, and many trees were downed. There was a citywide power outage.
d. On a clear day, I can see the top of Murphy Monument from my house. If it's clear tomorrow, I'll be able to see the monument
