It also doesn't work setting the option1 as null like.
{
"product":{
"body_html":"Every element of IntelliMouse Pro - from its unique arched shape to the texture of the rubber grip around its base - is the product of extensive customer and ergonomic research. Microsoft's popular wheel control, which now allows zooming and universal scrolling functions, gives IntelliMouse Pro outstanding comfort and efficiency.",
"created_at":"2014-04-28T11:19:43",
"published_at":"2014-04-28T11:19:43",
"product_type":"Mice",
"title":"Microsoft IntelliMouse Pro",
"vendor":"Warner",
"published":true,
"sku":"MSIMPRO",
"variants":[
{
"option1":null,
"option2":null,
"option3":null,
"sku":"MSIMPRO",
"barcode":null,
"price":"49.99",
"compare_at_price":null,
"position":1,
"inventory_management":"shopify",
"inventory_policy":"deny",
"fulfillment_service":"manual",
"requires_shipping":true,
"taxable":false,
"inventory_quantity":null,
"created_at":null,
"grams":null
}
]
}
}