What is the origin of the character 对/對?
well, to make a reasonable guess; have a look of 漢語多功能字庫, please.

對 (u+5c0d) is a character since 甲骨文 (oracle bone script), which is composed by component "丵" (u+4e35), "土" (u+571f), &amp;  "又 - 手" (又 originally means right hand).

3 pictures of 對 in oracle bone script:



then, 丵 in small seal script (i can't find this one in oracle bone script at this moment)


土 in oracle bone script


又 - 手 in oracle bone script


the synopsis in this page is:

手持工具開闢土地


the initial meaning of 對 is "using hand (又 - 手) tools (丵) to develop land (土)".

later, in 金文 (bronze script), the form of 對 is slightly changed:


闢地分疆﹒植樹於土﹒立下地界


the meaning of 對 at this time is "planting tree along the boundary of the newly developed land"

with nowadays technology, one might think of "building a fence to protect an area" (e.g. set up barbed wire fence to encircle a farm)

then,

後假借為應對、應答之意


對 was "borrowed" to have the meaning of "response", "reply" or "answer"; which matches of the first two explanations in 國語辭典

http://dict.revised.moe.edu.tw/cgi-bin/cbdic/gsweb.cgi?o=dcbdic&amp;searchid=W00000002366

imo, chopping "對" into "業" &amp; "寸"; errh . . . . "off course" :(

imo, quoting "帝作邦作對" to support the above meaning is appealing.

here's the poem 皇矣 ( with James Legge's english translation)

作之屏之﹒其菑其翳
脩之平之﹒其灌其栵
啟之辟之﹒其檉其椐
攘之剔之﹒其檿其柘


verses in the second group is, opened up, made clearing in forest, paved the area. 

then, in third group:

帝省其山﹒柞棫斯拔﹒松柏斯兌


柞 has the meaning of "chop down trees"

帝作邦作對


邦 has the meaning of "planting tree as boundary", similar to 對. imo, "作邦作對" is rhetoric,  a "writing in pair". in modern chinese, we still have the saying: 作威作福, or, 作福作威

next, 業 is character since bronze script, which is a 象形字 (pictogram) of "rack for hanging bell, musical instruments". here're 2 samples of 業:


imo, 業 is, unlikely, derived from 對 or 丵.