A circle of radius 1 is surrounded by 4 circles of radius r as shown. What is r ?

**Answer Choices**

A. \sqrt{2}

B. 1+\sqrt{2}

C. \sqrt{6}

D. 3

E. 2+\sqrt{2}

A circle of radius 1 is surrounded by 4 circles of radius r as shown. What is r ?

**Answer Choices**

A. \sqrt{2}

B. 1+\sqrt{2}

C. \sqrt{6}

D. 3

E. 2+\sqrt{2}