If \(\rm \vec{a},\vec{b},\vec{c}\) are three non-zero vectors with no two of which are collinear, \(\rm \vec{a}+2\vec{b}\) is collinear with \(\rm \vec {c}\) and \(\rm \vec{b}+3\vec{c}\) is collinear with \(\rm \vec {a}\), then \(\rm |\vec{a} +2 \vec{b}+6\vec{c}|\) will be equal to

• A. Zero
• B. 9
• C. 1
• D. None of the above