Answer:
1) B) An increase in the literacy rate. While a literate worker will probably be more productive than a illiterate worker, the effect of literacy on productivity is indirect, not direct. Besides, some activities do not require literacy: many blue collar jobs have been carried out by people who can't read for millenia, and their productivity does not directly depend on the capacity to read and write.
2)D) Increasing the amount of capital. Because the more capital there is, the more of it can be invested in production, and the more of it is invested, the higher the output.