Final answer:
The gesture of seesawing both palms alternately up and down generally signifies 'maybe,' but the question seems to have been mixed with physics conventions, where a downward motion is assigned a negative sign and forward and to the right are considered positive directions. Option c is the correct answer.
Step-by-step explanation:
The gesture described, holding both palms out and 'seesawing' them alternately up and down, is commonly used to convey uncertainty or indecision, which corresponds to the word 'maybe' (option b). However, this question appears to be a mix-up with two different topics. The provided reference information relates to conventions in physics regarding the assignment of signs to directions of motion, which is separate from the sign language gestures mentioned. Still, to clarify the provided reference:
Sign Convention in Physics
Conventionally, an object moving downward is assigned a negative sign (option b). Meanwhile, for the orientation of axes, forward and to the right are typically considered positive directions (option c).
It's important to mention the correct option in the final answer. In this case, for the gesture, the correct option is b. 'maybe.' For the physics-related questions, the mentioned correct options in the final answer are b and c for their respective questions.