insist on,keep up,carry out,stick to這幾個詞怎麼區分?

題目：

insist on,keep up,carry out,stick to這幾個詞怎麼區分?
No matter what you say,I shall stick to my own opinion.
爲什麼這題選stick to?

解答：

stick to 在此作「堅持」解
insist on +doing
keep up +doing
carry out好象也是堅持的意思
但是從語意上來說Stick To會準確點