Final answer:
The consensus decision scale among the options given is '3) -2, -1, 0, +1, +2', which represents a spectrum of attitudes towards a decision from strong disagreement to strong agreement.
Step-by-step explanation:
The scale used to evaluate a consensus decision in the options provided is: 3) -2, -1, 0, +1, +2. This scale reflects a range of attitudes or positions towards a proposal in a decision-making process, particularly when seeking consensus. The negative values show varying degrees of disagreement or discomfort (-2 being strong disagreement, -1 being mild disagreement), 0 represents neutrality, and the positive values represent agreement (+1 being mild agreement, +2 being strong agreement).