Final answer:
The incorrect statement is c) because it incorrectly describes minimal pairs as forms placed according to their articulation on a phonetic chart, rather than as word pairs with only one phonological difference and distinct meanings.
Step-by-step explanation:
The incorrect statement among the options provided is c) Minimal pairs consist of forms that are placed along the horizontal axis with respect to their place of articulation and the vertical axis to their manner of articulation. This description is more relevant to the organization of a phonetic chart, where sounds are placed according to their place and manner of articulation, rather than to the concept of minimal pairs. A minimal pair in linguistics consists of two words that differ in only one phonological element and have different meanings, as stated in a) and d). Option b) is also correct, as minimal pair testing is a method used to determine whether two sounds are different phonemes or allophones of the same phoneme within a specific language. The minimal pair test observes if the substitution of one sound for another results in a change of meaning, indicating that the two sounds are separate phonemes.