B. Scientists believe that in the past penguins were ... 1) as big as penguins today. 2) bigger than penguins today. 3) smaller than penguins today.

Правильный ответ: 2) bigger than penguins today. В тексте сказано: "But scientists think that 37 million years ago there were penguins that were 2 metres tall and weighed as much as 115 kg."