Respuesta :
C. However
"As well as" and "similarly" both show similarity, not contrast, so A and B are not correct. "At the same time" can be used to show contrast, but "however" is always used to show contrast, so it is the correct answer.
"As well as" and "similarly" both show similarity, not contrast, so A and B are not correct. "At the same time" can be used to show contrast, but "however" is always used to show contrast, so it is the correct answer.