There are many natural _____ to help people fight common illness such as colds and upset stomachs.

remedies 意為「療法、藥物、補救措施」。natural remedies 是英文常見固定搭配，指「自然療法或偏方」。代入句中意為「有許多自然療法能幫助人們對抗感冒等常見疾病」，語意與邏輯完全吻合。