The correct answer is: by forcing characters to trust each other and work together to solve a serious problem facing humanity.
Why: In science fiction, themes of teamwork are often explored through high-stakes scenarios that require collaboration among diverse characters. The focus on serious problems that threaten humanity inherently emphasizes the need for individuals to overcome differences, build trust, and utilize their unique strengths collectively. This approach not only highlights the importance of teamwork but also showcases how collaboration can lead to innovative solutions in the face of adversity. Other options, while they may also involve teamwork, do not emphasize the critical and overarching importance of trust and unity in addressing significant challenges.