Each of Two Vectors $\overrightarrow { \mathrm { D } } _ { 1 }$

Multiple Choice

Each of two vectors, $\overrightarrow { \mathrm { D } } _ { 1 }$ and $\overrightarrow { \mathrm { D } } _ { 2 }$ ,lies along a coordinate axis in the xy plane.Each vector has its tail at the origin,and the dot product of the two vectors is $\overrightarrow { \mathrm { D } } _ { 1 } \cdot \overrightarrow { \mathrm { D } } _ { 2 } = - \left| \overrightarrow { \mathrm { D } } _ { 1 } \right| \left| \overrightarrow { \mathrm { D } } _ { 2 } \right|$ .Which possibility is correct?

A) $$\overrightarrow { \mathrm { D } } _ { 1 }$$ and $$\overrightarrow { \mathrm { D } } _ { 2 }$$ both lie along the positive x axis.
B) $\overrightarrow { \mathrm { D } } _ { 1 }$ lies along the positive x axis. $\overrightarrow { \mathrm { D } } _ { 2 }$ lies along the negative x axis.
C) $\overrightarrow { \mathrm { D } } _ { 1 }$ and $\overrightarrow { \mathrm { D } } _ { 2 }$ both lie along the positive y axis.
D) $\overrightarrow { \mathrm { D } } _ { 1 }$ lies along the negative x axis. $\overrightarrow { \mathrm { D } } _ { 2 }$ lies along the negative y axis.
E) $\overrightarrow { \mathrm { D } } _ { 1 }$ lies along the positive y axis. $\overrightarrow { \mathrm { D } } _ { 2 }$ lies along the negative x axis.