d =2.55.68m and t = 11.36s
In my opinion
The answer that best fits the blank is the term WAXING. The moon is waxing whenever it reaches to the period that its phases are transitioning from new to full. The answer is the first option. This is when it is more that half is illuminated. Hope this helps.
Wave speed = (wavelength) x (frequency)
= (4 m) x (2 /sec)
= 8 m/sec
