Plzzz what forms a dune and a sandbar? select one: a. a sandbar is formed by wind. a sand dune is formed by water. b. a sandbar is formed by water. a sand dune is formed by wind. c. both are formed by wind. d. both are formed by water.

The temperature at a point (x, y) is t(x, y), measured in degrees celsius. a bug crawls so that its position after t seconds is given by x = 6 + t , y = 8 + 1 3 t, where x and y are measured in centimeters. the temperature function satisfies tx(3, 9) = 5 and ty(3, 9) = 4. how fast is the temperature rising on the bug's path after 3 seconds? (round your answer to two decimal places.)