The yoyo is just one of many toys that have an interesting history. in 1931 a man named d. r. duncan advertised his version of the yoyo and it quickly became a huge fad in the united states. children of all ages have played with yoyos much the same way for years. however, the materials to make this toy have changed. early yoyos were made of wood, metal, and clay. today many yoyos are made of a durable plastic. few people know that yoyos were the first toy to travel to space.

which sentence would be the best concluding statement for this paragraph?
a) some people consider the yoyo to be the second oldest toy in history.
b) in 1985 and again in 1992, nasa sent yoyos on its space shuttles.
c) the sales of yoyos have gone up and down, like a yoyo.
d) but, yoyos were wildly popular in the 1930s.