你是一个出版公司的数据库开发人员，对特定的书名的每天的销售情况建立了如下的存储过程：

CREATE PROCEDURE get_sales_for_title

title varchar(80), @ytd_sales int OUTPUT

AS

SELECT @ytd_sales = ytd_sales

FROM titles

WHERE title = @title

IF @@ROWCOUNT = 0

RETURN(-1)

ELSE

RETURN(0)

另外建立了一个脚本执行这个存储过程，如果执行成功，将返回对应于书名的每天的销售情况的报表，如果执行失败，将返回“No Sales Found”，怎样建立这个脚本？

Ａ. DECLARE @retval int

DECLARE @ytd int

EXEC get_sales_for_title ‘Net Etiquette’, @ytd

IF @retval < 0

PRINT ‘No sales found’

ELSE

PRINT ‘Year to date sales: ’ + STR (@ytd)

GO

Ｂ. DECLARE @retval int

DECLARE @ytd int

EXEC get_sales_for_title ‘Net Etiquette’, @ytd OUTPUT

IF @retval < 0

PRINT ‘No sales found’

ELSE

PRINT ‘Year to date sales: ’ + STR (@ytd)

GO

Ｃ. DECLARE @retval int

DECLARE @ytd int

EXEC get_sales_for_title ‘Net Etiquette’,@retval OUTPUT

IF @retval < 0

PRINT ‘No sales found’

ELSE

PRINT ‘Year to date sales: ’ + STR (@ytd)

GO

Ｄ. DECLARE @retval int

DECLARE @ytd int

EXEC @retval = get_sales_for_title ‘Net Etiquette’, @ytd OUTPUT

IF @retval < 0

PRINT ‘No sales found’

ELSE

PRINT ‘Year to date sales: ’ + STR (@ytd)

GO