Correct use of customerS

I am writing a cover letter for a resume. In the two sentances below, which is the correct form of customerS:

customers

customer's

customers'

1)




/* Font Definitions */
@font-face
{font-family:"Century Gothic";
panose-1:2 11 5 2 2 2 2 2 2 4;
mso-font-charset:0;
mso-generic-font-family:swiss;
mso-font-pitch:variable;
mso-font-signature:647 0 0 0 159 0;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{mso-style-parent:"";
margin:0in;
margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:10.0pt;
font-family:"Century Gothic";
mso-fareast-font-family:"Times New Roman";
mso-bidi-font-family:"Times New Roman";}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.25in 1.0in 1.25in;
mso-header-margin:.5in;
mso-footer-margin:.5in;
mso-paper-source:0;}
div.Section1
{page:Section1;}
I am effective in assessing the customers needs and abilities with hardware and software technology.

2)




/* Font Definitions */
@font-face
{font-family:"Century Gothic";
panose-1:2 11 5 2 2 2 2 2 2 4;
mso-font-charset:0;
mso-generic-font-family:swiss;
mso-font-pitch:variable;
mso-font-signature:647 0 0 0 159 0;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{mso-style-parent:"";
margin:0in;
margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:10.0pt;
font-family:"Century Gothic";
mso-fareast-font-family:"Times New Roman";
mso-bidi-font-family:"Times New Roman";}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.25in 1.0in 1.25in;
mso-header-margin:.5in;
mso-footer-margin:.5in;
mso-paper-source:0;}
div.Section1
{page:Section1;}
I believe in a proactive and follow-up review approach until the customers are comfortable and satisfied.

Thank you