Harlow and Zimmerman's Classic Research Regarding Freud's Views of Feeding

Harlow and Zimmerman's classic research regarding Freud's views of feeding practices and the attachment process indicated that

A) Freud was correct in assuming that the feeding process plays the central role in establishing parent/child attachments.
B) breast feeding is far superior to bottle feeding with regard to promoting parent/child attachments.
C) contact with a soft, cuddly caregiver is more important than specific feeding practices with regard to the establishment of parent/child attachments.
D) attachments are biologically programmed, therefore feeding becomes irrelevant in the attachment process.