Correct Option (B)
Assumption 2 is valid. The passage explicitly states that "Malnourished mothers have low levels of this sugar in their milk. Consequently, the microbiomes of their infants fail to mature. That in turn, leads to malnourished babies." This establishes a direct causal link, indicating that infants of malnourished mothers are prone to malnutrition due to the impact on their gut microbiome development.
Incorrect Options:
Assumption 1 is not valid. The passage describes the problem of immature gut microbiomes in malnourished children and links it to the absence of a specific sugar in the mother's milk. However, it does not mention or propose processed probiotic foods as a solution or treatment for this condition. Therefore, making an assumption about the efficacy of probiotic foods based solely on this passage is unwarranted.