Which sentence best shows correct comma usage?

How does this image the reader to understand seismographs?

When i was four years old, my dad and i a tree in our front yard. it was a tiny, fragile sapling. he promised me that it would grow tall and strong, but he said that i had to be patient. until i turned 18 years old, dad and i it every year on my birthday. choose the words that correctly fill in the blanks.

How can you avoid the problem of groupthink? a. by choosing a group leader to direct the group b. by composing the team of only like-minded individuals c. by encouraging all members to voice their opinions d. by keeping quiet when you disagree with another group member's opinion