Which of the following might be true of an individual unable to synthesize and secrete intrinsic factor?
a. They would be unable to absorb adequate amounts of $\operatorname{vitamin} \mathrm{B}_{12}$
b. They would be unable to digest lactose found in dairy products.
c. They would be unable to absorb amino acids in the small intestine.
d. They would be unable to digest and absorb triglycerides.