While on His Way Home, Jack Buys a Box of Guardian

While on his way home, Jack buys a box of Guardian Original cereal and a family pack of Rice Krispies for his kids.He does not ponder the benefits provided by the competitors' products.This is an example of:

A) habitual decision making.
B) internal search for information.
C) postpurchase dissonance.
D) impulse buying.
E) external search for information.