What is the correct markup for alt attribute of an image?
alt
<img src="cubism.jpg" alt="Version of ""Whistler's Mother"" in cubist style">
<img src="cubism.jpg" alt='Version of "Whistler's Mother" in cubist style' />
<img src="cubism.jpg" alt="Version of \"Whistler's Mother\" in cubist style">
<img src="cubism.jpg" alt="Version of "Whistler's Mother" in cubist style">