Which sentence uses an effective transition?

I signed my puppy up for obedience classes because she chewed up all my shoes.

Lots of kids signed up for the race as the school needed to make three different time slots.

So Marcus’s computer stopped working due to he had to get a new laptop.

Leila lost her favorite necklace, consequently she found it in the garbage can.

The sentence that uses an effective transition is:

Leila lost her favorite necklace; consequently, she found it in the garbage can.

The use of the transition word "consequently" effectively shows the cause-and-effect relationship between losing the necklace and finding it in the garbage can. This transition signals that the second part of the sentence is a result of the first part.