To go a bit farther,
DN15 uses designating and resistance contact in asking three questions which I will number:
1). If the qualities, traits, themes, & indicators by which there is a description of name-group (mental activity) were all absent, would designation-contact with regard to the form-group (the physical properties) be discerned?"
2). "If the permutations, signs, themes, and indicators by which there is a description of form-group were all absent, would resistance-contact with regard to the name-group be discerned?"
3). "If the permutations, signs, themes, and indicators by which there is a description of name-group and form-group were all absent, would designation-contact or resistance-contact be discerned?"
.....and then it makes a sort of conclusion:
"Thus this is a cause, this is a reason, this is an origination, this is a requisite condition for contact, i.e., name-and-form.
Is 1) asking "if we could not describe mental activity could we then discern physical properties?"...... And similarly for 2) and 3)?